【作者】 范公俊；

【导师】 朱伟； 钱学德；

【作者基本信息】 河海大学 ， 岩土工程， 2007， 硕士

【摘要】 淤泥是一种水利、环境工程中大量产生的废弃土，通过固化处理将其转化为固化淤泥是目前一种有效的资源化利用途径。对于固化淤泥，物理力学性质的研究已经比较多，但是对于收缩性质的研究还未见报道。由于固化淤泥的含水率较高，水分的蒸发会带来土体收缩，从而导致固化淤泥的开裂、耐久性降低等不利影响，因此必须明确固化淤泥的收缩性质并提出有效的控制措施，才能更好的促进淤泥固化技术的工程应用。本文通过收缩试验对固化淤泥的收缩性质进行了研究，从固化作用的角度对收缩性质存在差异的机理进行了探讨，并分别以砂和石膏作为添加料探讨了控制固化淤泥收缩的措施。本文的主要工作如下： (1) 对不同初始含水率、水泥添加量和养护龄期固化淤泥收缩性进行了试验，并利用稳定体积收缩率和收缩比两个指标对其收缩性进行分析发现：固化淤泥的体积随含水率的减小而减小，并最终趋于一个稳定值；初始含水率越小、水泥添加量越高、养护龄期越长，其收缩比和稳定体积收缩率均越小，收缩性越小。 (2) 利用无侧限抗压强度试验、孔隙率试验和液塑限试验研究了固化过程对淤泥的胶结作用、填充作用和土性改良作用，并分析了固化作用与收缩性之间的关系，揭示了固化淤泥收缩的影响因素：胶结作用、填充作用、土性性质。胶结作用使固化淤泥具有骨架支撑效应、填充作用使得固化淤泥收缩空间减小、土性改良效应使得固化淤泥土颗粒自身收缩性降低，这三种作用均影响了固化淤泥的收缩性。 (3) 通过添加砂土和石膏进行收缩试验，发现它们均对固化淤泥的收缩性有明显的控制作用。添加砂土越多，其孔隙填充效应越明显，收缩控制效果越好。添加石膏能够提高骨架支撑作用从而使收缩性降低，但同时也提高了塑性指数导致收缩性增强，在骨架支撑和塑性指数提高两者共同作用下，固化淤泥收缩性存在最低值。更多还原

【Abstract】 Much dredged material occurred in the projects of hydraulic engineering, environment engineering and civil engineering. The solidification method is a resultful method of disposing the dredged material. The mechanics property of solidified dredged material has been fully studied, but the shrinkage property of solidified dredged material is not so clear. The high water content of solidified dredged material leads to high shrinkage which cause serious damage to the project. We should see the importance of the shrinkage property of solidified dredged material. In the paper, the shrinkage property and shrinkage control was studied.The main contents are as follows:(1) By indoor experiments of dredged material shrinkage in different levels of solidified dredged material. And it shows the shrinkage laws of solidified dredged material .To the solidified dredged material of different initial water content , cement addible quantity and curing time , its volume decrease with the smaller water content , then go to a stabilization value The solidified dredged material with lower initial water content, higher cement addible quantity and longer curing time has smaller shrinkage.(2) By analysing the experimental result of unconfined compressive strength, porosity and liquid and plastic limits, we can know the influence factor of shrinkage is the result of the variety of solidified effect: the effect of frame supported and pore filling induced the resistant function in dredged material shrinkage process by frame and packing filling; the soil property improvement made the shrinkage property of soil grain decrease, so did the shrinkage property of solidified dredged material.(3) Adding sand has remarkable function to decrease the shrinkage property of solidified dredged material. It was achieved by reducing the pore ratio, and it can improve the structure strength but can’t affect the soil property of solidified dredged material. Adding gypsum can control the shrinkage of solidified dredged material, and the adding quantity exist an optimized value. The gypsum can’t change the pore ratio, it can improve the structure strength but is disadvantage to the soil property.更多还原